关键词: 薄壁结构, 热声载荷, 非线性响应, 屈曲, 跳变, 试验验证

Abstract: To address the nonlinear response to thin-walled structure with large deflection under thermal-acoustic load, a thermal-acoustic excitation test and its corresponding simulation analysis for clamped metallic thin-walled plates have been implemented. The calculated results and the test results are consistent, verifying the effectiveness of the calculation method and the numerical model for thin-walled plate subjected to thermal-acoustic loadings. Based on these findings, the dynamic response calculation for a stiffen-reinforced plate structure under different thermal-acoustic load combinations is completed. Based on the obtained time-domain displacement response, analyses on structure vibration behaviors are mainly focused on three typical motions of the post-buckled plate, indicating that the relative strength between the thermal load and the acoustic load determines the Snap-through forms of the plate. The Probability Density Functions (PDF) of the displacement response are drawn by employing statistical analysis showing that the PDF of post-buckled plate exhibits double peak phenomena. Then the Power Spectral Density (PSD) functions are used to analyze the variations of response frequencies and their corresponding peaks with the increase of temperatures, as well as the determination of softening and hardening areas of the plate. At last, this paper discusses the variation of tensile stress with compressive stress in pre/post buckling areas, and gives the reasons for this kind of change. The work represented in this paper can provide some reference for dynamic response analysis and dynamic strength design of thin-walled structures subjected to thermal acoustic loadings.

Key words: thin-walled structure, thermal-acoustic load, nonlinear response, buckling, snap-through, test verification